Crystallographic study of self-organization in the solid state including quasi-aromatic pseudo-ring stacking...

1-Benzoylthioureas contain both carbonyl and thiocarbonyl functional groups and are of interest for their biological activity, metal coordination ability and involvement in hydrogen-bond formation. Two novel 1-benzoylthiourea derivatives, namely 1-benzoyl-3-(3,4-dimethoxyphenyl)thiourea, C₁₆H₁₆N₂O₃S, (I), and 1-benzoyl-3-(2-hydroxypropyl)thiourea, C₁₁H₁₄N₂O₂S, (II), have been synthesized and characterized. Compound (I) crystallizes in the space group P-1, while (II) crystallizes in the space group P2₁/c. In both structures, intramolecular N-H...O hydrogen bonding is present. The resulting six-membered pseudo-rings are quasi-aromatic and, in each case, interact with phenyl rings via stacking-type interactions. C-H...O, C-H...S and C-H...π interactions are also present. In (I), there is one molecule in the asymmetric unit. Pairs of molecules are connected via two intermolecular N-H...S hydrogen bonds, forming centrosymmetric dimers. In (II), there are two symmetry-independent molecules that differ mainly in the relative orientations of the phenyl rings with respect to the thiourea cores. Additional strong hydrogen-bond donor and acceptor -OH groups participate in the formation of intermolecular N-H...O and O-H...S hydrogen bonds that join molecules into chains extending in the [001] direction.